OMB APPROVAL
                                                           OMB Number: 3235-0058
                                                       Expires: January 31, 2002
                                                        Estimated average burden
                                                     hours per response. . .2.50


                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                  FORM 12b-25

                                                                 SEC FILE NUMBER
                                                                    CUSIP NUMBER

                          NOTIFICATION OF LATE FILING

(Check One):  [_] Form 10-K   [_]  Form 20-F   [_]  Form 11-K   [X] Form 10-Q
[_]  Form N-SAR

For Period Ended:  March 31, 2001
[] Transition Report on Form 10-K
[ ] Transition Report on Form 20-F
[ ] Transition Report on Form 11-K
[ ] Transition Report on Form 10-Q
[ ] Transition Report on Form N-SAR
For the Transition Period Ended: ___________________

Read Instruction (on back page) Before Preparing Form. Please Print or Type.
   Nothing in this form shall be construed to imply that the Commission has
   verified any information contained herein.

If the notification relates to a portion of the filing checked above, identify
the Item(s) to which the notification relates:
________________________________________________________________________________

  PART I -- REGISTRANT INFORMATION

   CAIS Internet, Inc.
   --------------------
   Full Name of Registrant

   N/A
   ---
   Former Name if Applicable

   1255 22nd Street, NW
   ---------------------
   Address of Principal Executive Office (Street and Number)

   Washington, DC  20037
   ----------------------
   City, State and Zip Code



PART II -- RULES 12b-25(b) AND (c)
If the subject report could not be filed without unreasonable effort or expense
and the registrant seeks relief pursuant to Rule 12b-25(b), the following should
be completed. (Check box if appropriate)
     (a) The reasons described in reasonable detail in Part III of this form
     could not be eliminated without unreasonable effort or expense;
     (b) The subject annual report, semi-annual report, transition report on
     Form 10-K, Form 20-F,11-K or Form N-SAR, or portion thereof, will be filed
 [X] on or before the fifteenth calendar day following the prescribed due
     date;
     or the subject quarterly report of transition report on Form 10-Q, or
     portion thereof will be filed on or before the fifth
     (c) The accountant's statement or other exhibit required by Rule 12b-25(c)
     has been attached if applicable.

PART III -- NARRATIVE
State below in reasonable detail the reasons why Forms 10-K, 20-F, 11-K, 10-Q,
N-SAR, or the transition report portion thereof, could not be filed within the
prescribed time period.
(Attach Extra Sheets if Needed)

  Additional time is required to complete final review of the material to be
filed.

PART IV-- OTHER INFORMATION

(1) Name and telephone number of person to contact in regard to this
notification

   (Name)   Andrew P. Hines, Chief Financial Officer
            ----------------------------------------
   (Area Code)  202
                ---
   (Telephone Number)  715-1796
                       --------

(2) Have all other periodic reports reports required under Section 13 or 15(d)
of the Securities Exchange Act of 1934 or Section 30 of the Investment Company
Act of 1940 during the preceeding 12 months or for such shorter period that the
registrant was required to file such report(s) been filed? If answer is no,
identify report(s).  [X]  Yes    [_]  No
________________________________________________________________________________


(3) Is it anticipated that any significant change in results of operations from
the corresponding period for the last fiscal year will be reflected by the
earnings statements to be included in the subject report or portion thereof?
[_]    Yes     [X]   No
If so, attach an explanation of the anticipated change, both narratively and
quantitatively, and, if appropriate, state the reasons why a reasonable estimate
of the results cannot be made.


   CAIS Internet, Inc.
   --------------------
(Name of Registrant as Specified in Charter)
has caused this notification to be signed on its behalf by the undersigned
hereunto duly authorized.
Date  May 15, 2001        By   Andrew P. Hines, Chief Financial Officer
      ------------             ----------------------------------------